Power amplifiers are used in a wide variety of communications and other electronic applications. These amplifiers are made up of one or more cascaded amplifier stages, each of which increases the level of the signal applied to the input of that stage by an amount known as the stage gain. Ideally, the input to output transfer of each stage is linear; a perfect replica of the input signal increased in amplitude appears at the amplifier output. In reality, however, all linear amplifiers have a degree of non-linearity in their transfer characteristics. This non-linearity results in a distortion of the output signal so that it is no longer a perfect replica of the input. This distortion produces spurious signal components known as intermodulation products. Intermodulation products are undesirable because they cause interference, cross talk, and other deleterious effects on the performance of a system employing power amplifiers. Accordingly, the prior art reflects various methods and devices designed to reduce the distortion produced during a power amplifier circuit's operation. Two methods commonly suggested are predistortion and feed forward. Both methods are well known in the art, therefore no further discussion is provided herein. Regardless of the type distortion reduction employed in the power amplifier circuit's design, it would be extremely advantageous to provide a method and apparatus for evaluating the circuit's intermodulation performance, and in response thereto, adjusting various operating parameters to optimize the power amplifier circuit's performance.